Relative expression of human myosin heavy chain isoforms by Real Time PCR in different muscles

In the present work we designed and tested different human specific primers and TaqMan probes for Real Time PCR in order to carry out a relative expression analysis of MHC isoforms in human skeletal muscle. In particular, we analyzed muscles with different composition in fibre types: skeletal muscles as gluteus, vastus lateralis, masticatory muscle as masseter and laryngeal muscles as tyroaritenoideus (ventricolaris and vocalis portion), interarytenoideus, cricothyroideus and the posterior portion of cricoarytenoideus. TaqMan probes provided reliable results in isoform-specificity for MHC 2A, 2X, 1/β-slow, α-cardiac, and perinatal (or neonatal) isoforms. This was confirmed by the expression of type 1, 2A and 2X MHC isoforms in the “control” muscle, vastus lateralis. Real Time PCR revealed high expression of α-cardiac MHC in masseter muscle, confirmed by protein electrophoresis, and a weak expression of the same isoform in laryngeal muscles. The specificity of perinatal MHC probe was confirmed by its expression in masseter only, where the perinatal MHC isoform was already described.